There’s a compelling desperation to much of John Hillcoat’s work – a seething, a clawing, a straining-to-survive in a world that seems indifferent and unforgiving at best and actively predatory at worst. “Gritty” suggests itself. “Ruthless” does nicely. His protagonists, set-jawed, tired-eyed men often caught between two irreconcilable inevitabilities or in the tangles of an impossible decision, strive against wounds corporal, emotional, and psychic in a landscape swaddled by corruption, murder, and greed.

Pairing Hillcoat, then, with “Triple 9” – a twisting, ensemble yarn of doublecross and dirty-coppery in which good is often bad and bad is almost invariably worse – would seem a sound and promising (ahem) proposition. Whereas the director’s previous outings have been set in past or projected timelines, alternate or isolated realities that may at best only invite pointed comparisons with our own, the Atlanta-set, aggressively “real” “Triple 9”marks Hillcoat’s first opportunity to spin a tale of human frailty that’s happening right here, right now. As is often the case, the extent to which the narrative lands or not may depend at least partly on the viewer’s expectations sitting down.

In Georgia’s apparently-crime-ridden capital city, here doing its best approximation of “Robocop”-era Detroit, Chiwetel Ejiofor’s Michael Atwood leads a sub-rosa gang of police, ex-police, and ex-military mercenaries obliged to pull off a pair of increasingly tricksy, increasingly high-stakes, occasionally pyrotechnic data thefts to sate the desires of the Kate Winslet(!)-headed Jewish-Russian mob to whom they are in hock. Very soon, it becomes apparent that certain of said gang (a trigger-happy Collins, Jr.) are more comfortable with the particular brand of carnage and casualty required than are others (Mackie, as an active-duty gang-unit officer named Marcus). Ties begin to fray when the first job goes a bit screwy thanks to the sloppiness of junkie-loose-cannon Gabe (Aaron Paul), and, with the police force now alerted and a near-impossible mission to break into Homeland Security (beat THAT, Ocean’s Eleven), the crew decide to buy time for the heist by creating what the film tells us is the ultimate calling-all-units distraction: the titular “triple nine,” or 999 – police code for “officer down.”

Enter Chris Allen (Casey Affleck): idealistic, new to the force, and Marcus’s new partner. He gnaws gum, meets everyone and everything with an unflappable Mona Lisa smirk, wants “to make a difference.” He is, it is summarily decided, the perfect mark. What then unfolds is a somewhat Byzantine cat-and-cat-and-mouse-and-more-cats-and-other-cats-dressed-as-mice game, as the appointed time approaches, various dramatic arcs play out, and the important questions (Will Mackie do it? Since they’ve got Ejiofor’s kid, he’s kind of a good guy, right? Are those fake teeth on Woody Harrelson?) are blurred, come into focus, and get re-blurred again.

With Hillcoat at the wheel and a humiliation of casting riches, “Triple 9” rolls into town behind prohibitively towering expectations. The fact is, it’s a serviceable crime drama, with solid set pieces and some nice acting moments (Mackie and Affleck forge a genuine and endearing chemistry; Harrelson adds some characteristic oddball charm; Michael K. Williams does much with a brief but vibrant cameo), but it seems to fall short of what its pedigree might suggest. Some acting beats miss marks, some plot turns are foreseeable, some dialogue feels like frank exposition. The result, alas, is conventional: something like a pulpier “Heat,” or a less-kinetic “The Departed.” Which, depending what you’re up for, might be fine.